Abstract

We present a fit to measured moments of inclusive distributions in B{yields}X{sub c}l{nu} and B{yields}X{sub s}{gamma} decays to extract values for the Cabibbo-Kobayashi-Maskawa (CKM) matrix element |V{sub cb}|, the b- and c-quark masses, and higher-order parameters that appear in the heavy quark expansion. The fit is carried out using theoretical calculations in the kinetic scheme and includes moment measurements of the BABAR, Belle, CDF, CLEO, and DELPHI collaborations for which correlation matrices have been published. We find |V{sub cb}|=(41.96{+-}0.23{sub exp}{+-}0.35{sub HQE}{+-}0.59{sub {gamma}{sub S}{sub L}})x10{sup -3} and m{sub b}=4.590{+-}0.025{sub exp}{+-}0.030{sub HQE} GeV where the errors are experimental and theoretical respectively. We also derive values for the heavy quark distribution function parameters m{sub b} and {mu}{sub {pi}}{sup 2} in different theoretical schemes that can be used as input for the determination of |V{sub ub}|.

We present results for the moments of observed spectra in inclusive semileptonic B-meson decays to charm hadrons B{yields}X{sub c}l{sup -{nu}}. Moments of the hadronic-mass and the combined mass-and-energy spectra for different minimum electron or muon momenta between 0.8 and 1.9 GeV/c are obtained from a sample of 232x10{sup 6} {Upsilon}(4S){yields}BB events, collected with the BABAR detector at the PEP-II asymmetric-energy B-meson factory at SLAC. We also present a reevaluation of the moments of electron-energy spectra and partial decay fractions B(B{yields}X{sub c}e{sup -{nu}}) for minimum electron momenta between 0.6 and 1.5 GeV/c based on a sample of 51x10{sup 6} {Upsilon}(4S){yields}BB events.more » The measurements are used for the extraction of the total decay fraction, the Cabibbo-Kobayashi-Maskawa (CKM) matrix element |V{sub cb}|, the quark masses m{sub b} and m{sub c}, and four heavy-quark QCD parameters in the framework of a Heavy-Quark Expansion (HQE). We find B(B{yields}X{sub c}l{sup -{nu}})=(10.64{+-}0.17{+-}0.06)% and |V{sub cb}|=(42.05{+-}0.45{+-}0.70)x10{sup -3}.« less

We investigate the exclusive rare B{sub c{yields}}D{sub (s){nu}l{nu}l} and B{yields}D{sub (s)}l{sup +}l{sup -} (l=e, {mu}, {tau}) decays within the standard model and the light-front quark model constrained by the variational principle for the QCD-motivated effective Hamiltonian. The form factors f{sub {+-}}(q{sup 2}) and f{sub T}(q{sup 2}) are obtained from the analytic continuation method in the q{sup +}=0 frame. While the form factors f{sub +}(q{sup 2}) and f{sub T}(q{sup 2}) are free from the zero mode, the form factor f{sub -}(q{sup 2}) is not free from the zero mode in the q{sup +}=0 frame. We discuss the covariance (i.e. frame independence)more » of our model calculation and quantify the zero-mode contributions to f{sub -}(q{sup 2}) for B{sub c{yields}}D{sub (s)} decays. The branching ratios and the longitudinal lepton polarization asymmetries are calculated with and without the long-distance contributions. Our numerical results for the nonresonant branching ratios for and B{sub c{yields}}D(D{sub s})l{sup +}l{sup -} are in the order of 10{sup -8} (10{sup -7}) and 10{sup -9} (10{sup -8}), respectively. The averaged values of the lepton polarization asymmetries obtained from the linear (harmonic oscillator) potential parameters are found to be -0.99 (-0.99) for B{sub c{yields}}D{mu}{sup +{mu}-} and -0.16 (-0.15) for B{sub c{yields}}D{tau}{sup +{tau}-}, and -0.98 (-0.98) for B{sub c{yields}}D{sub s{mu}}{sup +{mu}-} and -0.14 (-0.12) for B{sub c{yields}}D{sub s{tau}}{sup +{tau}-}, respectively.« less

We examine the anomalous dimension matrix appropriate for the phase space restricted B{yields}X{sub u}l{nu} and B{yields}X{sub s}{gamma} decay spectra to subleading nonperturbative order. The time ordered products of the HQET Lagrangian with the leading order shape function operator are calculated, as are the anomalous dimensions of subleading operators. We establish the renormalizability and closure of a subset of the nonlocal operator basis, a requirement for the establishment of factorization theorems at this order. Operator mixing is found between the operators which occur to subleading order, requiring the subleading operator basis be extended. We comment on the requirement for new shapemore » functions to be introduced to characterize the matrix elements of these new operators, and the phenomenological consequences for extractions of V{sub ub}.« less

We present measurements of R{sub Kl3{gamma}}{identical_to}{gamma}(K{sub L}{yields}{pi}{sup {+-}}l{sup {+-}}{nu}{gamma};E{sub {gamma}}*>10 MeV)/{gamma}(K{sub L}{yields}{pi}{sup {+-}}l{sup {+-}}{nu}), where l={mu} or e, and E{sub {gamma}}* is the photon energy in the kaon rest frame. These measurements are based on K{sub L} decays collected in 1997 by the KTeV (E832) experiment at Fermilab. With samples of 1385 K{sub L}{yields}{pi}{sup {+-}}{mu}{sup {+-}}{nu}{gamma} and 14221 K{sub L}{yields}{pi}{sup {+-}}e{sup {+-}}{nu}{gamma} candidates, we find R{sub K{mu}}{sub 3{gamma}}=(0.530{+-}0.019)% and R{sub Ke3{gamma}}=(4.942{+-}0.062)%. We also examine distributions of photon energy and lepton-photon angle.

In the quark-flavor mixing scheme, {eta} and {eta}{sup '} are linear combinations of flavor states {eta}{sub q}=(uu+dd)/{radical}(2) and {eta}{sub s}=ss with the masses of m{sub qq} and m{sub ss}, respectively. Phenomenologically, m{sub ss} is strictly fixed to be around 0.69, which is close to {radical}(2m{sub K}{sup 2}-m{sub {pi}}{sup 2}) by the approximate flavor symmetry, while m{sub qq} is found to be 0.18{+-}0.08 GeV. For a large allowed value of m{sub qq}, we show that the branching ratios (BRs) for B{yields}{eta}{sup (')}X decays with X=(l{sup -}{nu}{sub l},l{sup +}l{sup -}) are enhanced. We also illustrate that BR(B{yields}{eta}X)>BR(B{yields}{eta}{sup '}X) in the mechanism withoutmore » the flavor-singlet contribution. Moreover, we demonstrate that the decay branching ratios for B{yields}{eta}{sup (')}K{sup [*]} are consistent with the data. In particular, the puzzle of the large BR(B{yields}{eta}{sup '}K) can be solved. In addition, we find that the CP asymmetry for B{sup {+-}}{yields}{eta}K{sup {+-}} can be as large as -30%, which agrees well with the data. However, we cannot accommodate the CP asymmetries of B{yields}{eta}K* in our analysis, which could indicate the existence of some new CP violating sources.« less